Although claiming to be faithful to mix between the lawful and the unlawful is the act of disobeying God, as well as destroying his own property even in the Koran has clearly mentioned about the prohibition of mixing the halal with the haram because it willingness to obey depends on the level of faith a man who believes in Allah and as we live we must repent.
it's because we stole someone's treasure then we are arrested with the police pack.